1. Field of the Invention
The invention relates to an electrical connection device for connecting at least one stripped conductor end, with a bus bar piece and with a clamping spring which acts as a compression spring on the conductor end, the bus bar piece having a conductor through opening and a contact section which borders the conductor through opening and extends in the conductor through direction, the clamping spring having a clamping leg, an attachment leg and a roughly U-shaped sheet which connects the contact leg and the attachment leg, and the contact section together with the free end of the clamping leg forming a spring force clamping connection for the electrical conductor which is to be connected. In addition, the invention also relates to a bus bar piece with a conductor through opening and an angled contact section for use in an electrical connection device as well as an electrical terminal with a housing and with at least one electric connection device.
2. Description of Related Art
Electrical terminals are known in a host of embodiments. The terminals can be made for connection of an electrical conductor to a circuit board as so-called print terminal or for connection to another conductor as terminal block. Clamping springs are both loop-shaped clamping springs, so-called tension spring clamps, as also roughly U-shaped clamping springs into which rigid conductors or conductors provided with one wire end ferrule can be directly inserted, i.e., without the clamping site having to be opened beforehand with a tool. In the known loop-shaped tension springs, according to their names, the conductor to be connected is drawn by the clamping leg against a bus bar. In contrast, for U-shaped clamping springs the conductor to be connected is pressed by the clamping leg of the clamping spring which is acting as a compression spring against the bus bar or a region of a metal part.
Electrical terminals with a clamping spring which acts as a compression spring in addition to a generally plastic housing have at least one connection device which is held and located within the housing and which consists of a clamping spring and a metal part. The U-shaped clamping spring has a clamping leg and an attachment leg, the clamping leg together with a region of the metal part forming a spring force clamping connection for the stripped electrical conductor which has been inserted into the electrical terminal.
The metal part is used, first of all, for transmission of a current between the contact site with an electrical conductor and a second contact site which can be, for example, a contact site to a circuit board or also a contact site to a second conductor. In the latter case, the metal part is used for transmission of a current from a first electrical conductor which is connected to a first spring force clamping connection to a second conductor which is connected to a second spring force clamping connection. Moreover, the metal part can also be used for holding the clamping spring and especially for lateral guidance of the inserted conductor, for which the metal part, in addition to a base leg and the contact leg, has at least one side wall which runs essentially perpendicular thereto and which prevents the stripped conductor end from being pulled laterally out of the region of the clamping site.
An electrical terminal with this metal part is known, for example, from German Patent Application DE 10 2008 039 232 A1. The metal part has a relatively large-area side wall from which a contact leg, a base leg and an attachment leg are bent on three different sides of the side wall. The contact leg together with the clamping leg of the clamping spring forms the spring force clamping connection for an electrical conductor which is to be connected. The attachment leg of the clamping spring adjoins the attachment leg of the metal part which is opposite the contact leg, as a result of which the clamping spring is held in the metal part. Additional holding and fixing of the clamping spring take place by means of a pin formed in the housing. The current is transmitted from the conductor which has been inserted in the contact site to a second contact site via the base leg which runs perpendicular to the contact leg.
German Utility Model DE 20 2005 005 369 U1, likewise, discloses an electrical terminal which has at least one connection device which consists of a clamping spring and a metal part. The metal part is made as a channel-like, U-shaped trough with a base leg and two longitudinal legs, one end of one longitudinal leg being bent such that the end runs perpendicular to the two longitudinal legs and to the base leg. The end which has been bent, in this way, forms the contact leg which, together with the clamping leg of the clamping spring, forms the spring force clamping connection for the electrical conductor which is to be connected.
A similar metal part is also disclosed in German Utility Model DE 20 2007 012 429 U1. There, the metal part also has a base leg and two longitudinal legs which are bent perpendicular therefrom, the contact leg also being formed by the bent end of a longitudinal leg. Moreover, in this metal part, there is a reinforced bottom section in which a fold section is folded by one of the two longitudinal legs and is located oppositely on the bottom of the base leg.
It is common to the known metal parts that they are punched out of a flat metal strip and are then brought into their finished form by bending-over individual sections. The disadvantage here is that they require increased material use which is not determined solely by the required current carrying capacity.
Moreover, there are also electrical terminals or electrical connection devices which, in addition to a clamping spring, have a bus bar or a bus bar piece as metal part. This terminal with a corresponding connection device is known from German Patent DE 28 25 291 C2. In this known terminal, the bus bar has a conductor through opening through which the stripped conductor end can be inserted. A perforated collar which is closed in a ring shape adjoins the conductor through opening in the conductor through direction. The inner wall of the perforated collar which is opposite the free end of the contact leg forms a contact section which with the clamping leg of the clamping spring forms the spring force clamping connection for an electrical conductor which is to be connected. It is described in this document that it is advantageous that the conductor through opening which is closed in a ring shape with the deployed perforated collar ensures reliable accommodation and guidance of the conductor end which is reliably grasped and clamped by the clamping leg which projects into the conductor through opening without the risk of individuals cores of a flexible conductor being able to give way laterally.
A similar electrical connection device is also disclosed by European Patent Application EP 1 391 965 B1 which also discloses a bus bar with a conductor through opening and a perforated collar which adjoins it and which is closed in a ring shape. If the bus bar piece is relatively narrow, so that the conductor through opening is bordered laterally only by relatively narrow edge webs which run in the longitudinal direction of the bus bar, the execution of the perforated collar which is closed in a ring shape has the advantage that the cross sections of the perforated collar are moreover also current lead cross sections so that in spite of the relatively narrow lateral edge webs altogether a relatively large current lead cross section is available in the longitudinal direction of the bus bar piece for the current transmission.
By using a flat bus bar with a conductor through opening and a perforated collar closed in a ring shape instead of a relatively large-area metal part the required material use can be reduced, but as before the execution of the perforated collar by punching or deep drawing in the production process of the bus bar requires a material feed which is distinctly greater than the width of the bus bar piece which is to be produced.